1. Field of the Invention
This invention relates to roof or wall structures, and more particularly to improvements in joint retention clips for maintaining the elements of a rib-like joint in assembled relation in the region between adjacent panel support members.
2. Description of the Prior Art
Roof structures are known wherein profiled panel members are erected in side-by-side relation and secured to panel support members such as purlins or girts. Adjacent panel members are connected by interlocked marginal edges to form joints. Joint retention clips are installed in the joints between adjacent panel support members.
A profiled panel member and a joint retention clip are disclosed in application Ser. No. 249,062 (BOYER) filed Mar. 30, 1981 and assigned to the assignee of this invention and now U.S. Pat. No. 4,400,922. Each panel member presents spaced-apart longitudinal ribs, and male and female partial ribs along opposite longitudinal edges thereof. The partial ribs of adjacent panel members, when assembled in overlapped relation, form a rib-like joint which simulates one of the longitudinal ribs.
A number of problems arise in joints employing the BOYER joint retention clip. For example, the BOYER clip has a clip sidewall which is interposed between overlapped outer and inner sidewalls of the male and female partial ribs. For a short distance on either side of the clip sidewall, the inner and outer rib sidewalls are spaced-apart forming gaps on the weather side of the joint. During inclement weather, water may enter the gaps and eventually corrode the clip. Clip corrosion may result in long term structural deterioration of the joint and short term deterioration of the appearance of the roof due to rust streaking onto the panel face.
Two applications of sealant are required to fully encapsulate a top wall of the clip, that is, one beneath and another over the top wall of the clip. The possibility exists that moisture, introduced into the joint by capillary action, may find its way between one layer of the sealant and the clip--again resulting in corrosive deterioration of the clip.
As is known, the shape of a male partial rib may vary from the intended shape because of roll forming tolerances or because the male partial rib has been deformed during field-handling. As designed, the BOYER clip cannot accommodate shape variations of the male partial rib.
The BOYER clip presents a second clip leg engaged with the male partial rib, which resists vertical disengagement of the interlocked partial ribs. As designed, the second clip leg is inclined at an angle of about 40.degree. relative to the vertical. Because of the large angle of inclination, the applied vertical load which can be resisted by the second clip leg--without collapse by bending--is limited and less than would be desired.